Aldi's reign as cheapest supermarket ends as rival knocks it off the top spot
Lidl overtook Aldi to snatch the cheapest supermarket title in October, according to the latest monthly analysis from Which?.
We compared the prices of 44 popular grocery items in October and found the total average cost was £74.58 at Lidl – just 17p less than its closest rival, Aldi.
When we compared average costs for a trolley of 135 items, in which we didn't include Aldi or Lidl, Asda was cheapest.
Here, we reveal how the UK's eight biggest supermarkets compare for pricing.
Cheapest supermarket for a basket of groceries
Our basket of 44 items included Albert Bartlett Rooster potatoes, own-brand chicken and milk.
The chart shows how much our basket cost on average at the UK's eight biggest supermarkets:
Lidl was the cheapest supermarket in October overall: our shop cost £74.58, just 17p less than Aldi's basket cost of £74.75
The same basket of items at Waitrose would have set you back an average of £91.15 – that's 22% pricier than Lidl.
When it came to the 'big four' supermarkets, our comparison revealed that Asda was the cheapest for our basket, at £82.11.
- Find out more: how to spend less at the supermarket
How do bigger shopping lists compare?
We also compared the cost of a larger trolley of 135 items (the original 44, plus 91 more).
These products included a larger number of branded groceries, including Bird’s Eye frozen garden peas and Heinz cream of chicken soup. As the discounters don’t always stock big-brand products, we haven’t included Aldi or Lidl in this comparison.
The graph shows how much our larger trolley cost on average at each supermarket:
Asda was the cheapest for our trolley of groceries, a title it's held for every month since January 2020 – except for July 2023, when Morrisons pipped it to the post.
Our trolley cost £328.42 at Asda, comfortably beating the next cheapest supermarket Morrisons by £10.98.
Our analysis also unveiled that Waitrose was £49.66 pricier than Asda on average, with our big shop costing £378.08 at the upmarket store.
- Find out more: best and worst supermarkets
Loyalty pricing affecting the rankings
After being named the most expensive supermarket for a big shop last month, Sainsbury’s is now second priciest for those shopping without a loyalty card, followed by Tesco.
This has pushed Ocado, which was traditionally in the top two most expensive supermarkets alongside Waitrose, into fourth place.
Which? believes this may be due to an increased emphasis on loyalty pricing – where Tesco Clubcard and Sainsbury’s Nectar members get lower prices on some items – which appears to have pushed average prices up for those who aren't members of the schemes.
We don’t include loyalty prices in our supermarket price comparison as these aren’t available to everyone.
- Find out more: Sainsbury's adds personalised Nectar prices online
How Which? compares supermarket prices
We look at the prices of hundreds of grocery items at eight major supermarkets every day throughout the month, using an independent price comparison website.
We calculate the average price of each item at each supermarket across the month, before adding those up to get stores' average prices for a basket and trolley of products.
To keep things fair, we include special offers but not multibuys or loyalty-scheme discounts in our analysis.
Our shopping list includes branded items such as Cathedral City extra mature cheddar and PG Tips teabags, as well as own-label products such as smoked bacon rashers and little gem lettuce.
As own-brand items aren't identical across supermarkets, we use experts to ensure everything we’ve compared is as similar as possible, based on several factors including quality and weight.
- Find out more: supermarket price comparison over time
What's happening to supermarket prices?
Year-on-year price rises for food and drink dipped slightly to 12.4% in the three months to 30 September 2023, according to Which? research.
Our latest figures – which we release every month – show that Sainsbury's has the highest level of inflation, with prices up 14% year on year in the month of September. This is the first time Sainsbury's has been highest for inflation, possibly due to it offering more discounts only to Nectar card holders, which appears to have pushed up average prices for non-members.
Our inflation data is based on supermarkets' standard prices, and doesn't take into account multibuys or loyalty scheme discounts.
Sainsbury's was followed by Lidl at 13.3%.
When it comes to types of food, biscuits are still the fastest rising in price of all 20 categories in our research. Chocolate, crisps and yoghurts are also among the worst-hit categories.
- Find out more: Which? food price inflation tracker
Which? calls on supermarkets to do better
Which? has found that, while some good practice exists, many of the major supermarkets have not done enough to support their customers during the cost of living crisis.
Supermarkets could be doing more by ensuring their smaller convenience stores stock budget-range healthy food, especially in areas where this is most needed.
Given the urgency of the cost of living crisis, Which? is calling on the government to act now and work with supermarkets to secure changes that could make a real difference to millions of people struggling to put food on the table.
- Do you want to see your supermarket take action to support people through the cost of living crisis? Sign our Affordable Food for All petition
